| Popis: |
Cementing is an important link in the process of oil and gas well construction. The quality of cementing directly affects the safety of next drilling, recovery capacity and life of later production. It is very important to accurately reflect and describe the dynamic changes of various underground parameters in the process of cementing for reasonable control of construction measures and guarantee the quality of cementing replacement. Based on the study of the dynamic process of cementing, the field equation is simplified to ID model by using the principle of momentum conservation and mass conservation, and the calculation model of cementing dynamic parameters at any time considering the effect of U-shaped pipe is established, including bottom hole pressure, friction, height and volume of vacuum section, static pressure in pipe and annulus, ECD and other dynamic parameters. The initial value problem is solved numerically by iterative method. The software of cement slurry flow simulator is developed, which is used to visually simulate the cement slurry flow process. The numerical model development software can be used to visually simulate the dynamic flow process of cement injection, which is suitable for complex wellbore structure and multi fluid injection. It can simulate the whole flow process of cement injection well, including the generation of U-tube effect, and analyze the variation law of dynamic parameters. The software can be used to simulate the dynamic flow process of cement injection, which is suitable for complex wellbore structure and multi fluid injection including the generation of U-tube effect, and analyze the variation law of dynamic parameters. Field data of a well was verified, and the results show that the proposed method can accurately calculate the flow parameters in the whole process of cementing, and can be used to guide the design of cementing operation. The innovation of this paper is to develop the simulation software of cementing slurry dynamic process. The function modules of the software use numerical model instead of empirical formula to improve the calculation accuracy of each parameter. The software has comprehensive functions, and gives the dynamic parameter change law of each stage in the fixed construction process. It has strong practicability and can well meet the requirements of on-site construction. |
